NATIONAL TRANSPORTATION SAFETY BOARD Vehicle Recorders Division Washington, D.C. 20594 December 21 , 2001 Air Traffic Control Recording Specialist’s Report by Joseph A. Gregor A. ACCIDENT Location: New York, New York Date: September 1 1 , 2001 Time: 1 Aircraft: Boeing 767-200ER NTSB Number: DCA01 SA060 B. GROUP N/A C. SUMMARY On September 11, 2001 American Airlines Flight 11, a Boeing 767 crashed into Tower 1 of the World Trade Center in New York City, New York. A certified analog copy of air traffic control (ATC) transmissions recorded on September 11, 2001 at various tower, departure, and Air Route Traffic Control Center (ARTCC) positions along the route of flight was sent to the audio laboratory of the National Transportation Safety Board. These recordings were used to create an audio track and text transcript of the aircraft-ground communications from takeoff to accident time. - II - D. DETAILS OF INVESTIGATION Transmissions between the accident aircraft and ATC were recorded and an analog copy was sent to the Safety Board’s audio laboratory. The tapes cover the following ATC positions and time periods: Facility Time Period 1 (UTC) Position BOS 1152:37-1217:48 LCE BOS 1155:32-1210:49 ID (B) 1157:42-1210:00 SL ZBW 1205:32- 1208:50 “1 Sector 47R ZBW 1204:51 -1233:59 Sector 46R Sections of the tape recordings containing air-ground transmissions to and from the incident aircraft were digitized at a 22,050 Samples/second data rate and saved as standard Microsoft .wav files. Individual .wav files were combined into a single 35 minute 12 second long .wav file containing all transmissions to and from the incident aircraft from 1159:02 UTC (aircraft cleared for takeoff) to 1234:14. A transcript was obtained from the final composite recording. Times are approximate due to limitations inherent in the data obtained from the FAA. Joseph A. Gregor l r Electrical Engineer - Ill - Transcript of ATC communications with a Boeing B-767-200ER (American Airlines flight 11) which crashed into Tower 1 of the World Trade Center in New York City, New York on September 11, 2001. LEGEND AAL-11 Radio transmission from American B-767-200ER, flight 1 1 LCE Radio transmission from Local Control East ID (B) Radio transmission from Initial Departure position B SL Radio transmission from Lincoln Departure 47R Radio transmission from Sector 47 Radar position 46R Radio transmission from Sector 46 Radar position * Unintelligible word # Expletive ( ) Questionable insertion [ ] Editorial insertion Pause — Interruption Note 1: Times are expressed in universal coordinated time (UTC). Note 2: Only radio transmissions to and from the accident aircraft were transcribed. Note 3: Words shown with excess vowels, letters, or drawn out syllables are a phonetic representation of the words as spoken. 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[BOS 1155-1210 Initial Dept.] INTRA-COCKPIT COMMUNICATION AIRCRAFT-TO-GROUND COMMUNICATION 00 O CO © LU »- o o O LU $2 1§ UJ O o O UJ tr O => O' lb CO i/> m CO O CD « £ CO CD 03 lO (0 O CD CD > jD CD § •c CD E < o i— c © o E CO , — , ‘■g O *5. l^Q 11 0 ) _ £ £ CO o> ° ^ "o — E 5 o 5 is 9-V CC ID c 40 O To o CD X 5 CO o 10 u- 3 ^ g 2 "8 5 CD o < N CD CO CD CD > 03 CD CO O CD o C/3 C CD > _© CD S 0) E < _ IS 03 — CO © O *= ■o® «£! SuS 5 «> c JI CD > CO CD O |o © 'f- g T g)tn o Vb» £ co w §.§ 3 C/3 o £ >» 2 P > © © r- © o c o © > T 3 © C © O) © . — , © -C CL c^Q ii lo I r^- lo © © IS - co © C DQ 8|c 1 i i I ® □ O™ lo o CD |w © o J= CD © o © © 03 m © 8 > •r— © ® w E i < I r^* cm _ Tf CD o ' CMQ CM 00 t- CM lO CO T- M" T- LO • • LO • • • • 1 V 1 o . CM -J o CM T- < T- < r- CO -T— AAL-11 * seventy American eleven. [BOS 1157-1210 L-incoln Dept.] INTRA-COCKPIT COMMUNICATION AIRCRAFT-TO-GROUND COMMUNICATION 00 O IU O o O UJ br o 2, a: x* 05 r- CM t- CO t- CD CO 5 • • |o • • m o • • | m J. o • | in o 5! in 0 a: in 0 — co CM — J CM < CM 3 CM s CM h~ T- CO T- < xf 0 ) CD CD i h- uO CO o CD jD 0 ) c 8 *C » CD £ £ © © JD i « 8 *C CD E < 2 k O 1 ° CD • — ' “ 6 CD t- > =J jD O CD tl if o CO a> E < CD CD O BL CD oQ ll £ □ CD O © r- hr CM >*l^ n in _ *o *- ® c o E cd T5 < cd c ^ E CD CM O C r- E °N © o C CM O T- co _ O O CD t * ■o o o 05 © o E "8 o 05 © § o 1 o o CD 0 ^ h- xj- 8 O 2 V © CD N CO CD ^ £ *- _C= CM o rL £ ° ^ CM CD © ' - > CO I ®o CD 8 a> o — co 52 co o CD CD Q_ CD © 3 O CD m a : % c ID Si h © .9* CD E < CD C *CD E co UJ X a co o CD © > _© CD 8 *C CD E < C£ LD H CO III O S' T5 £ |o ■o -5 o © © CO IM ^ © T— © CM L. t— JH I o O £ 2 © > © CO o 5 S' o ^ CD 3 ® x* CM O 1o o CD *0 CD I r- o CM CO O CD CO o CD © > _© a) 8 *•■1 CD E < CD O © o ■ — , M £ CD • > 2 ® 5 ro [§> 0 © 1 I I §- CD O © O © CO CD > xl- CD t- co CM C © o S r- xr • • co o DC CM N- O T- lO T-. • # ■ 00 o CM 05 O CM a uj hr o 2, a: E "° CO AAL-11 Boston center good morning American eleven with you passing through one ninerzero for two three zero. [BOS 1204-1233 Sector 46R] INTRA-COCKPIT COMMUNICATION AIRCRAFT-TO-GROUND COMMUNICATION 00 O U1 © o c ® TO CO O CO p CO .9 CM "7 t- rr © o CD CM O T— co 3 o ga " o' XI t_ =J CD e N o ^ to cd o © ® o © ^ o CD '/n ^ 0) CD If £ i S’ J= < E CD CM CM « • o> ^ o 0l CM CO CO CO CM 1 o CM CO O CD CD O CD > CD § a: E CM _© r- ® CO g O 8 a ■§ 6 I ® < N O G CD CO co CO CM 1 o CM CO o 00 CD > © CD 8 *C CD E < CD IM CO o O CD o 0 _0 CD P O ° CD O * c CD > © CD 8 *C © E < 0 , , to © © I o CM CO o CD CD *C C/5 © © w 05 © *o >N © % E 13 c 5T © CD > xr _© . © 8 8 © E < o G © CO is? I 5! o G © CO CO cO CM CM CO O CD © > © 8 *C © E < 05 u_ >» ® S 5^ CO • • CM CO in CM 00 un • • ^ 01 CM CO M 1 r- 05 T — O CD CD a> > CD CD C 'co E _Q E o' CD u_ O t> cd CO co co =§2 a) > _o cd co o o CM co O CD CD o ^ © < N a: CD M- o ts CD co CO CO CM o CM CO o CD o To o CD c a) > a> a> CD C CO o 'u CD E < h- uo • • £ a: CM CD 00 O « • ? a: CM s c CH CD CO =3 _CD CD 8 32 CO O CD CD T3 t_ O c 8 C o To o CD u. CO CD s§ C o cd T3 > CD © CO ® CO CO CM CD c/) co V Cl -go: -— CD t- CD CD a 0 T3 CD c co 2 CO To co O CM CD 1 CO o © CM °n >N O it= JO c: • CD CD ~0 © 2 o 8 CD E < CD co CD > CD CO o © N lt= ° o CD > _Q) CD CO O *C CD E < o c CD O c o To o CD c o: CD CD > ^ 2 • CD 8 O T5 CD CO Is Is m CM O) CM CM xf; CO • • • • 2 tc 2 a: !£ a: ^ a: CM CD CM CD CM CD CM CD t- T“ T“ ^ 1217:05 46R American eleven, American one one Boston. [BOS 1 204-1 233 Sector 46R] INTRA-COCKPIT COMMUNICATION AIRCRAFT-TO-GROUND COMMUNICATION 00 n CM CD x- JD CD S ‘C CD E < co CD O >s o TD , , 5 O CD SZ M- g o o B CD g CO CO CO CM T — I o CM CO o CD t CD S CD E < _a> CD 8 CD E < CD O CD a: CD O « CD CO co CO CM i M- O CM CO O CD c o V o CD CD > jD CD 3 *c CD E < CO CO CM CO o CD o~ c CD > a) CD c | a> cd E CD < co a: CD i O V CD CO cO co CM i M- O CM CO O CD t CO o o « :: © © CO . CO r- CO §5! > i c S co 5! © (0 ’= ° O"c0 co ^ V 5 * e- .3 CO CO o Q _co CL CD E o co CD > co CD 5 CD CD £ CO ££ § CD CO CO CM o CM s v of CD CO CD £ o T 5 CD CO co CO co o CD _Q = >*CM OD O>o S *o % c CO © ® O > = CD CD 3 ■— • O o lo 2 - c 0 ^ >» o ■g E« •§ C CD .2, o 00 Q_ CO vT CM co CD i o CM o O co CD n “ O > c/j C CD II CD c CD 3 * CO c CO co S CD Q_ XL CD 2 E 2 TD CD CD > CO CD E 1159:02 LCE 1159:11 1159:14 1159:16 1200:11 1200:19 1200:30 1200:36 1200:43 1201:19 1201:21 1202:14 1202:16 1203:03 1203:06 1203:34 1203:37 1204:27 1204:32 1204:48 1204:52 1204:55 1205:14 1205:19 1205:32 AAL-11 LCE AAL-11 LCE AAL-11 AAL-11 ID (B) AAL-11 ID (B) AAL-11 ID (B) AAL-11 ID (B) AAL-11 ID (B) AAL-11 ID (B) AAL-11 AAL-11 SL AAL-11 SL AAL-11 AAL-11 American eleven heavy traffic's orbiting north of the field at thirty five hundred feet maintain three thousand runway four right, cleared for takeoff. [BOS 11:52-1217 LCE] maintain three cleared for takeoff on four right, what are the winds? [BOS 11:52—1217 LCE] wind three three zero at niner. [BOS 11:52-1217 LCE] ***. [BOS 11:52-1217 LCE] American eleven heavy contact departure that traffic* s now in your ten o’clock and two miles thirty four hundred feet. [BOS 11:52-1217 LCE] * we have him in sight and going to departure so long American eleven heavy. [BOS 11:52-1217 LCE] departure good morning American eleven heavy with you passing through ah two thousand for three thousand. [BOS 11:55-1210 Initial Dept.] American eleven heavy Boston departure radar contact good morning traffic ten o* clock two miles maneuvering Cessna Skylane VFR at three thousand five hundred. [BOS 11:55-1210 Initial Dept.] . . we have him in sight American eleven. [BOS 11:55-1210 Initial Dept . ] American eleven heavy climb and maintain eight thousand. [BOS 11:55-1210 Initial Dept.] eight thousand American eleven heavy. [BOS 11:55-1210 Initial Dept . ] American eleven heavy turn right heading one eight zero. [BOS 11:55-1210 Initial Dept.] one eighty American eleven heavy. [BOS 11:55-1210 Initial Dept.] . _ , American eleven heavy climb and maintain one four thousand. [BOS 11:55-1210 Initial Dept.] one four thousand American eleven heavy. [BOS 11:55-1210 Initial Dept.] American eleven heavy turn right heading two two zero. [BOS 11:55-1210 Initial Dept.] two zero American eleven. [BOS 11:55-1210 Initial Dept.] American eleven heavy turn right heading two seven zero contact Boston approach one two seven point two good day. [BOS 11:55- 1210 Initial Dept.] twenty seven two and two seventy American eleven so long. [BOS 11:55-1210 Initial Dept.] American eleven heavy with you passing through one zero thousand for one four thousand. [BOS 11:57-1210 Lincoln Dept.] American eleven heavy Boston approach fly heading two seven zero. [BOS 11:57-1210 Lincoln Dept.] * seventy American eleven. [BOS 11:57-1210 L— incoln Dept.] American eleven heavy contact Boston center one three three point four two. [BOS 11:57—1210 Lincoln Dept.] thirty three forty two so long American eleven. [BOS 11:57-1210 Lincoln Dept.] Boston center good morning American eleven with you passing through one one thousand for one four thousand. [BOS 1207-1214 Sector 47R] American eleven Boston center good morning climb maintain flight level two three zero proceed direct CHESTER. [BOS 1207- 1214 Sector 47R] 1205:36 47R 1205:41 1208:47 1208 : 50 1209:17 1209:22 1209:25 1210:13 1210:15 1211:58 121204 1213:29 1213:31 1213:47 1213:57 1214:08 1214:23 1214:33 1215:15 1215:22 1215:49 1216:32 1217:05 1217:56 1218:56 1220:08 1222:27 1224 : 33 1224:36 1224 : 38 1224:46 1224:53 1224 : 56 AAL-11 47R AAL-11 AAL-11 46R AAL-11 46R AAL-11 46R AAL-11 46R AAL-11 4 6R 46R 46R 4 6R 46R 46R 46R 46R 46R 46R 46R 46R 46R 46R 4 6R AAL-11 AAL-11 46R 4 6R AAL-11 two three zero direct CHESTER American eleven. [BOS 1207-1214 Sector 47R] . . , . American eleven contact Boston center one two seven point eight two. [BOS 1207-1214 Sector 47R] twenty seven eighty two so long American eleven. [BOS 1207 1214 Sector 47R] Boston center good morning American eleven with you passing through one niner zero for two three zero. [BOS 1204-1233 Sector 46R] . . . . . American eleven Boston uh center roger climb and maintain level two eight zero. [BOS 1204-1233 Sector 46R] two eight zero American eleven. [BOS 1204-1233 Sector 46R] American eleven climb maintain flight level two niner zero. [BOS 1204-1233 Sector 46R] niner zero American eleven. [BOS 1204-1233 Sector 46R] American eleven your traffic is at uh two o'clock two zero miles southwest bound MD-80 three one oh. [BOS 1204-1233 Sector 46R] American eleven roger. [BOS 1204-1233 Sector 46R] American eleven turn twenty degrees right. [BOS 1204-1233 Sector 46R] twenty right American eleven. [BOS 1204-1233 Sector 46R] American eleven climb maintain flight level three five zero. [BOS 1204-1233 Sector 46R] American eleven climb maintain flight level three five zero. [BOS 1204-1233 Sector 46R] American eleven Boston. [BOS 1204—1233 Sector 46R] American eleven Boston. [BOS 1204—1233 Sector 46R] American one one uh the American on the frequency how do you hear me? [BOS 1204-1233 Sector 46R] American eleven Boston. [BOS 1204—1233 Sector 46R] American eleven if you hear Boston center ident. [BOS 1204-1233 Sector 46R] American eleven if you hear Boston center ident please or acknowledge. [BOS 1204-1233 Sector 46R] American eleven if you hear Boston center ah re-contact Boston Center on one two seven point eight two, that’s American eleven one two seven eight two. [BOS 1204—1233 Sector 46R] American eleven, American one one Boston. [BOS 1204-1233 Sector 46R] American eleven if you hear Boston center ident please. [BOS 1204-1233 Sector 46R] American eleven Boston. [BOS 1204-1233 Sector 46R] American eleven American one one how do you hear the center? [BOS 1204-1233 Sector 46R] American eleven Boston. [BOS 1204-1233 Sector 46R] is that American eleven trying to call? [BOS 1204-1233 Sector 46R] **. [BOS .1204-1233 Sector 46R] we have some planes, just stay quiet and you'll be okay we are returning to the airport. [BOS 1204-1233 Sector 46R] and uh who's trying to call me here? [BOS 1204-1233 Sector 46R] American eleven are you trying to call? [BOS 1204-1233 Sector 46R] nobody move, everything will be okay, if you try to make any moves, you'll endanger yourself and the airplane, just stay quiet. [BOS 1204-1233 Sector 46R]